Who said there are small negatively charged particles inside an atom?

Find the mass in grams of 1.37x1020 particles of h3po4

Imagine that twenty i.u.’s of enzyme z were catalyzing the above reaction for one minute, under vmaxconditions, in a 3.00 ml assay volume. the assay is buffered with 20 mm phosphate buffer, ph 7.60. what will the ph be at the end of that one minute?

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2